Andrés Manuel López Obrador, presidential candidate for the Party of the Democratic Revolution (PRD), greets supporters as he arrives to a rally in Orizaba, in the Mexican State of Veracruz on Monday, June 4.

Across Latin America, the left – from the fiery nationalism of Venezuela to the more market-friendly left of Brazil – dominates. Even in places where leftists are not in power, they’re still a force to be reckoned with.

But in Mexico this election cycle, the left has only recently become competitive, less than a month before presidential elections July 1. After languishing in third place as he struggled to brand himself as a capable leader, Andrés Manuel López Obrador is now in second, though most polls show his rival, frontrunner Enrique Peña Nieto, with a comfortable lead.

Many say the left should be a powerhouse in Mexico, due to the country’s vast disparities between rich and poor. But the main leftist party, the Party of the Democratic Revolution (PRD), has never held the presidency.

Mr. López Obrador and his PRD almost won the previous election in 2006, and to some observers, he did. After his defeat he declared fraud and led sit-in protests that brought Mexico City to a standstill, alienating many of his supporters and dividing his party. But the left’s uphill battle this year is not just about the controversial candidate it has fielded or internal divisions in the party. The left is also hampered by Mexico’s unique history of one-party leadership under the Institutional Revolutionary Party (PRI), which is leading the race today. Founded in the wake of the Mexican Revolution, the PRI wielded socialist rhetoric and a vigorous nationalism that eclipsed and co-opted the message of the left. Put simply, many voters who tilt left in Mexico are drawn to the PRI instead of the PRD.

“[The PRD] is probably too close to the old regime, and that has been a very difficult problem for the left,” says sociologist Roger Barta, a professor emeritus at Mexico's National Autonomous University.

'AMLO'

Mexico has a long tradition of an intellectual left, popularized by writers and painters such as Diego Rivera. Its political party arose from the leftist faction in the PRI, which protested the rightward swing of some PRI party members.

López Obrador became the face of the PRD after his tenure as mayor of Mexico City from 2000 to 2006. In the 2006 presidential election, he presented himself as a fiery populist, denouncing oligarchs and promising that in his administration, the poor would be first.

Those words should have staying power in Mexico, where the gap between the rich and poor is vast: The world’s richest man, Carlos Slim, hails from Mexico, while more than 40 percent of Mexicans live on less than $2 a day. López Obrador, nicknamed AMLO or “el Peje,” after a tough freshwater fish from his native Tabasco, started his political career working on behalf of the indigenous in his home state and ran for governor in 1994, but lost.

He left Mexico City’s mayoral office with sky-high popularity thanks to social programs, like one that gave pensions to the elderly, and his shepherding of large infrastructure improvements. He is famous for leading mass protests in the name of democracy and social justice, appealing acts given Mexico's relatively recent foray into truly democratic, multi-party governance.

But López Obrador has since become a liability for his party. In 2006 his critics sought to portray him as the region's next Hugo Chavez, Venezuela's populist president. For those who didn't buy it, he later turned them off when he lost the 2006 race, staging a sit-in protest in downtown Mexico City. He refused to recognize the official results, instead declaring himself the nation's “legitimate president,” even holding his own inauguration and setting up an alternate cabinet.

His polarizing personality also caused deep fissures in his party. “All these divisions are becoming a burden [on] the left,” says Alberto Aziz Nassif, a specialist in democracy and civil society at the Center for Research and Higher Education in Social Anthropology in Mexico City.

Today, even though López Obrador has tried to moderate his message, focusing on creating a “loving republic,” eschewing the confrontational style that he long depended on to rally his base, it has been a struggle to regain lost ground.

More than an image problem

But even if López Obrador weren't the candidate – he competed for the PRD ticket against current Mexico City mayor Marcelo Ebrard, who is considered less radical – and the party were more unified, the PRD would still have faced a tough race.

The PRI's rule in the 20th century was not easy to categorize as right or left, but it was clearly nationalistic, appealing to campesino movements and unions, many of the same groups that vote for leftist issues like worker’s rights and land redistribution in the rest of Latin America. When opposition parties emerged to fight the PRI's hegemony, it was the conservative National Action Party (PAN) that became the clear opposition voice. The PAN won the presidency from the PRI after 71 years – while the PRD has had to vie for the same electorate traditionally drawn to the well-established PRI.

“The PRI took the space of the left,” says Mr. Aziz Nassif.

'PRI territory'

San Cristobal de las Casas, located in the highlands of southern Chiapas state, seems like a logical place for the left to have a sturdy foothold. The city was overtaken by the Zapatista rebels in 1994 who emerged the day that the North American Free Trade Agreement (NAFTA) went into effect and has since drawn anti-globalization leftists from across the world. It's also home to poor campesinos and indigenous communities.

The PRD did win the south in the 2006 presidential race, but that is largely because the PRI candidate was considered so weak, analysts say. Now PRI candidate Enrique Peña Nieto is outshining both the PRD and PAN in preliminary polls, making the left's fight for votes even more of a challenge. According to a poll by the Mexico City-based firm Mitofsky, the PRI has more followers than any of the other parties in Chiapas State.

On the way to San Juan Chamula, in the indigenous highlands near San Cristobal de las Casas, a sign on the road into town reads: “This is PRI territory.” The opinions of residents here show the party’s historic reach.

“We have always been with the PRI,” says Cristobal Collazo, who works in the tourism desk outside the town's famed church where Catholic and ancient Maya rituals are practiced.

For many who make up the PRI’s base, the race seemed to have a foregone conclusion until López Obrador began catching up. Now the man who has moderated his message might find himself painted as a radical by his rivals once again. In Villahermosa, the steamy capital of Tabasco state, Victoria Garcia Andrade, says she’s with the PRI because she fears the left: “We don't want what happened in other countries, like Cuba or Venezuela,” she says.

Of course, AMLO still has a base of hardcore followers. In fact, when asked why the left has not been able to win, they retort that it has – twice. They are referring to the 2006 race as well as one in 1988 in which the leftist candidate is largely believed to have won. They suspect the PRI of rigging that vote in its own favor.

This year, they hope to at last to see their candidate in the presidential palace, Los Pinos. Gladys Sanchez works at a jewelry shop on one of the main thoroughfares of San Cristobal. She says many people from Chiapas dismiss the PRD because they say it hasn't been in power and thus is not poised to navigate the economic problems and violence of Mexico. But she says the opposite is true. “We have tried the PRI and we have tried the PAN, it is time to give the PRD a chance,” she says.